The murderer and principal accused. Was born on 19th May 1910 in a Brahmin family, he was named Ramchandra but since he wore a nose ring as a child he was called Nathuram meaning Ram who wears a ring. Nathuram was a high school dropout. In various books he has been described as a qualified tailor and also a carpenter. He was a fanatical follower of V. D. Savarkar. Nathuram was associated with the Hindu Mahasabha. He worked with Savarkar as his secretary. He published and edited "Agrani" which was later rechristened "Hindu Rashtra".

He led a campaign to murder the Mahatma and finally succeeded in murdering him on 30th January 1948. Nathuram was sentenced to be hanged by the neck until dead. The execution was carried out at the Ambala Jail on November 15,1949.